Originally Posted by rbsangler
has the heat exchanger ever been tested, inspected or rplaced in that? Do you have a carbon monoxide detector reliably functioning in your home? 32 years is pushing the safe service life of any gas fired appliance. Be safe first....good luck with it.
Replaced, no. Tested- if you consider combustion analysis for CO in the exhaust a test, yes. We have 2 up-to-date CO monitors in the house. I agree with you, 32 years is a long time in the furnace world. I'm calling my furnace guy Monday. It appears the problem is the draft inducer system- either the motor/fan or partial blockage in the exhaust stack. The original inducer system was replaced 15 years ago. Probably overdue. I'm thinking maybe just a new inducer, maybe a new furnace. Either way, best to get this done before winter sets in for real.
The double-clutch furnace cycles are intermittent, which is a PITA to diagnose. But, I've able to narrow down the problem to either the inducer or the over-temperature sensor. Since the double-clutch can occur at the beginning, middle or near the end of a furnace cycle and the duct air temperature hasn't changed from what it was 10 years ago, my money in on the inducer blower.